In this work we study the effect of caffeine and taurine on the mobility of water molecules at 298 K using femtosecond mid-infrared and dielectric relaxation spectroscopy. We observe both molecules to have a slowing down effect on the mobility of surrounding water molecules: a single caffeine molecule slows down ~9 water molecules, a single taurine molecule slows down ~4 water molecules. The reorientation time constant of these slow water molecules is 4–5 times longer than the reorientation time constant of 2.5 ps of water molecules in bulk liquid water.

IOP Publishing
The Netherlands Organisation for Scientific Research (NWO)
Ultrafast Spectroscopy

Smit, W.J, van Dam, E.P, Cota, R.O, & Bakker, H.J. (2019). Caffeine and taurine slow down water molecules. J.Phys.Commun., 3(2), 025010: 1–025010: 7. doi:10.1088/2399-6528/ab07e4